Operation of cupola furnaces



.Dec. 4 1923.

' l.. J, RocHLlTz OPERATION CUPOLA FURNAGES ifm/MEX 7 Sheets-Sheet 4 www ' Dec. 4, 1923.

L. J. RocHLlTz OPERATION oF cUPLA FURNAcEs Filed'July 2, 1920 Dec.' 4 1923.

L. J. ROCHLITZ OPERATION obj cUPoLA FuRNAcEs Filed July 2. 1920 7 Sheelzs-Shee'l'l 5 Dec. 4, 1923.

Filed July 2, 1920 7 sheets-sheet 6 Hrm/Mik Patented Dec. 4, 1923's.r

UNE-rs.; si"

ics.

OPERATION OF CUIGLA FURNACES.

Application led July 2, 1920. Serial No. 393,753.

(GRANTED UNDER THE rnovrsions orA THE Aereos MARCH 3, 1921, 4i STAT. 1.,' 1313.) .f

To 'all 'whom t mayconcern:

Be it known that I, LUDWIG J osnr ROCH- Li'rz, citizen of Czechoslovakia, residing at Stuttgart, Wurttemberg, Germany, have invented certain new and and useful Improvements in the Operation of Cupola Furnaces (for which I filed applications in Germany, No. 42,168, July 26, 1915; Germany, No; 42,- 801, J an. 24, 1916; Germany, No. 42,802, Jan. 24, 1916; Germany, No. 42,996, Mar. 10, 1916) and I do hereby declare the following to be a full, clear, and exact description-of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in the operation of cupola-furnaces of the class in which liquid or gaseous combustibles are used as a fuel for melting and the object of my invention is to provide a new' Way or method of supplying the hearth of a furnace of the vclass referred to with material i intended forimelting by which'certain disadvantages heretofore inherent in the melting process with gases or liquid combustibles are entirely avoided. 'Another object of my invention vis to provide such improvements v in the construction of' ,furnaces of the said class, as may be necessary for carrying out my invention.

yIn describing my invention v'I refer to the drawings herewith in which Figure I is a longitudinal section through a 'furnace Y adapted for Vuse in carrying out my invento, namely, melting by means of cruc'ible furnaces, by means of flame-furnaces and by means of cupola-furnaces, the latter offering certain particular advantages of which the following are specially valued:

The heating power may be particularly uti-` lized on the counter-current system or principle; there is no interruption of operations;

the charge of a furnace may be put in por-` tions or lots and also'in various qualities, it

may then be vreduced intoliquid state ant when molten, drawn off 'through the tapmaterial intended for melting, ythe severall y,

layers of the 'former preventing not only contact of unmolten metal with material which is'still in a state of melting and in this wayl preventing any trouble which might arise out of such contact, but keeping at the! saine time this half-molten metal separate from metal already entirely molten, only the liquid material being allowed 4to trickle through. Y f

' lVfhere, however, liquid or gaseous fuel is employed, this is different and therefore certain ways must vbe followed which myA invention aims to provide, and, accordingly, the principal feature ,of my invention is to secure the` advantages enumerated by precluding in any of the various ways here-y inafter described an automatic forward movement -within the furnace, of the material intended for melting and instead the'reV of controlling and causingV such forward movement only in accordance with the 'advancing or advanced stages in the process of melting.L In this way the hearth is saved from a premature entrance or incursion of the insufficiently pre-heated material and, in addition, the melting may be done in various portions, an interstitial space or distance being provide'd'between the several portions in process of melting and each next following portion of unmolten material.

My invent-ion will be best understood by referring to the drawings illustrating vari? ous forms of furnace for practicinginy improved method. 1 Y

V'hug Figure I illustrates a furnace, as referred to, in longitudinal section ycomprising a hearth 7a, a shaft or tunnelsch, a wall t, a 'tap-'hole er, a burner Z),inspecltion-hole'sy so, a slide-rail, gs, a gate 6m through which to put in the charge, receptacles shereinafter referred to, a Solent, supports as and 1 a landing or platform g2). The shaft shows` an inclination of'about 35 degrees to'l per# a slipping down ofthe charge. The

latter I divide into lots or portions which I place in a kind of open boxes or receptacles s, preferably consisting of the same or a similar material as the material ins tended for melting and insert them, one after the other, through the gate into the inclined shafts in which they are thus allowed to severally slip or glide down, one after the other, their advance. Vmove-ment being controlled and only the lowermost portion permitted to go upon the hearth.

i' vWhen this lowermost portion and thereceptacle containing it is melted, the next following portion is bound to follow, while another j portion is being put int-0 the shafttch through the gate on top-end. A stopping stone. or thelike may be provided in the lower portion of the tunnel to halt the respective lowermost receptacle until its turn arrives, when it may be put on the hearth by means of any -suitable .device or constructive part which may be provided for the purpose, though not visible on the drawing. Another example of construction of the furnace is illustrated in Figure II, also shown in longitudinal section, this figure indicating again `the aforementioned parts, as the hearth it, the shaft or tunnel SGL, the wall t, the burner l), inspection-opening so,

Vthe sliding rail gs, the gate bm, the receptacles s, the sole ut, the supports u8 and the platform gb' and, in addition, a feeding or charging device be. `In this case the inclination of the shaft is about 25 degrees only.V The. several portions of the charge placed again in receptacles of about the same material as the one intended for melting I insert, as in the first described case, in a series, one after the other into the shaft lor tunnel, these receptacles to Vbe severally pushed forward with the result that the lowermost portion ygets .on the hearth, .while on top another new charge is 'being added. As soon as the lowermost portion together withv the receptacle containing it is melted, the next adjoining portion may be placed unto the hearth by operatingthe aforemen;

cles, as described, of about the same material `as thek one intended for melting, I insert, as

in the cases alreadydescribed, through the gate in successive series, but this time de tachably fastened to each other, the receptacles being each time suitably lowered,

thus getting upon thehearth'while anotherV charge is being added on to-p and a new porvtion isheing forwarded towards the hearth by another letting-down movement.

' All ofthe foregoing constructions of the cupola furnace. and the modes of Voperation applicable, require, as aforesaid, the feed to be chargedl in receptacles as described and though there is no difficulty in pre-Y paring or dressingthelatter, still the ways described for chargingv the furnaces illustrated require a certain amount'ofcare and attendance and some skill and, besides spe-V tions described hereinafter, where the for-V ward movement o-f thefeed will be effectuated by movements of the furnace itself, or,rather, by oscillating motions of Y the shaft or tunnel, as more particularly specified below.

Accordingly theconstructions shown in Figures IV, V, VI,'VII, designed more particularly for furnaces of smaller dimensions and adapted to be taken' to pieces, swing on pivots or trunnions and aiford,in addition, the advantage that repairs may be made on the inside and parts exchanged, whenever, forany reason, this maybe desired.

An example of a construction ofthisl kind is shown in Figure IV, being a view longitudinal section through such av furnace which shows again the-hearth t, a shaft or tunnel sch, a pair of tap-holes a1 Vplaced opposite each other, inspection holes so, a pivot e and platforms gb placed opposite each other, the said hearth being provided with ahearth-sto-ne hs. l

The forward movement of the charge is in this construction brought aboutby oscillating the shaft for about 130 degrees, about the pivot e, the shaft when in normal position showing aninclinationof 30 degrees,

more or less. The. hearth It, is of the doublesided type, the sides being alternately employable in the melting process which vaffords the ,advantage that the waste heat within the shaft or tunnel, acting in upward s direction will alternately benefit the two halves of the vault or ceiling of the furnace.

The dimensions in width of the hearth may, besides, be somewhat smaller than usual and the center fitted out with a hearthstone, preferably of such shape land so diseY intended each time. to be receivedfor melt.

ing. The said hearth-stone may also be placed on the bottom, direct upon the sole of the'furna'ce'fwhich permits the insertion each time `and the operation of an viron-bar of sutable width throughthe. respective `inspection-hole during the swinging motions to regulate the size of the portions getting upon the side of the hearth intended for the y respective 4sides of the hearth, thereby imparting a preliminary heating to the charge within theshaft.

I operate this modified construction vas followsr. The shaft resting against one of the platforms, I place the charge into the shaft in the usual way and swing it against the opposite platform, as indicated inthe ligure by dotted lines, the lowermost portion of the chargebeing lby the shaking of the shaft forwarded upon the hearth while another portion may be put :in on top through the gate at the same time and the charge thus replenished. As soon as the portion inV the hearth is melted, it may be Adrawnoff through the proper tap-hole and by another Y swing ofthe shaft against the former, now

opposite platform the next following portion may be-made to enter the hearth,

Another example of carrying out my invention is illustrated in Figure V which shows another modified constructionvof my furnace in longitudinal section. Ths gure shows the hearth 71 the hearth-stone hs, a shaft or tunnel 8071i, opposite tap-holes ar, opposite burners b, inspection holes so, a pivot e and opposite platforms gb, the said shaft having in this case alternately disposed interior transverse partitions gw. Also in this furnace the feed may be forwarded by to and fro swingings, this time for about l1() degrees, of the shaft, the normal position of the said shaft being at an inclination of about 35 degrees. The burners and the hearth are constructed and disposed approximately as described and shown with reference to the last foregoing modification of my construction and may be used in` about the same way. The shaft is, as already mentioned, provided with alternately disposed transverse partitions permitting its through thev proper tap-hole andby new repeated swngings from one platform against the other andv back again, thenext adjoiningportion may be forwarded into the hearth. Y 'v i In the constructions sh-own in Figures VI and VII the-feed is again forwarded byl movements of theshaft, but this time by axial rather than by swinging motions. Also these types are chiefly intended for smaller sizes and may be. taken apart, per-V mitting of repairs and the'exchange rof inner parts.

Accordingly Figure VI is a longitudinal section through a furnace of the last mentioned constructive principle. In this figure l?, is againthe hearth, 'he a hearthstone, 'sc/i the tunnel or shaft of thefurnace, so are inspection-holes, bare burners#q are rolle-rs 4or wheels which are provided instead of the pivot mentioned' in the last foregoing constructions, ar are'Y tap-holes and g?) is the platform. rI`he forward movement of the feed is in this instance effectuated by rotatory oscillations of' the furnace for 180 degrees which I bring about by means of'fmechanisin including' .the said rollers r. The inclinationV of the furnace in normal position is about 25 degrees. Otherwise thev furnace is for the fulfilment of the same dutiesof the same construction. as the furnace described in Figure V except that it has not the partitionsreferredltoin the former.

The operation is likewise the samel except Figure V, the same being also lshown i'n Y these partitions being, in fact, the only fea ture which distinguishes this construction from the one illustrated in the last foregoing figure. Also in this instance the forward movement of the feed is effectuated by axially reciprocating movements of the furnace, again for 180 degrees, byY means of the rollers r, the inclination of the furnace being about 25 degrees. The mannerof operation is also in this case as yabove re# peatedly set forth, particularly' in describing Figure- V, only thatl the furnace isron tated,'as in the last illustrated instance, instead of being swung. y

All of the constructions and methods of Voperation `described permit the melting of metals by means of liquid or gaseous `fuel with the same effect as -may be done -1n -a -cupola furnace'in which solid combustibles are employed as a fuel and without losing.`

any of the advantages residing in furnaces of the last-mentioned class.

I do not limit myself to the exact details of operation and the exact constructions and arrangements herein described and shown, as I desire to avail Imyself of such modificationsV and equivalents as fall properly Within the spirit of my invention.

,I claim l. The herein described' method of operating cupola furnaces employing` liquid or gaseous fuel, Which consists in subdividing a complete charge into parts, and successivelyfeeding the parts'of the charge in an inclined path to the furnace hearth so that one part is completely melted before a succeeding part is fedthereto.

' 2. .The herein described method of operating cupola furnaces employing liquidor gaseous fuel, Which consists in subdividing the charge into'parts, and imparting` motion to the furnace to feed the parts of the charge to the furnace hearth so that one part is completely melted before a succeeding part is fedthereto,

3. A furnace of the character described, comprising an inclined charge feeding shaft, a hearth at the loWer end of said shaft, burners adapted to direct liquid or gaseous fuel into -said hearth, and means for impartingA motion to the furnace to cause the feed of the chargethrough the shaft.

4. The herein described method of operating cupola furnaces, Which consistsin continuously feeding acharge towards the furnace hearth and permitting only a definite fraction of said charge to enter into the furnace hearth at a time.

5. The herein described method of operating cupola furnaces, which consists in con- Vin deiniteffractionail quantities and at certain determined intervals of time.

7. fr furnace of the character described, comprising a hearth,1a charge feeding path leading thereto, means for successively feeding charge from said path into said hearth in predetermined fractional quantities, and means operative upon the melting of a fraction ofsaid charge in the hearth for permitting the entrance of the succeedingV fractional quantity into the hearth.

in testimony whereof I hereunto aflix my signature in the presence of two Witnesses.

LUDVVIG JOSEF ROCHLITZ.

Vitnesses:

EUGENE SCHLEIGHER, ERNEST ENTENMANN. 

